Bone density scanning is an enhanced form of x-ray technology that is used to measure bone loss. DXA is today’s established standard for measuring bone mineral density (BMD). DXA is most often performed on the lower spine and hips. In children and some adults, the whole body is sometimes scanned. Occasionally when there is a hip replacement or lower back surgery there is metal. In those cases, a forearm is done as a second site. Therefore it will be ordered either as a bone density spine and hip or bone density extremity.
- DXA is most often used to diagnose osteoporosis, a condition that often affects women after menopause but may also be found in men. Osteoporosis involves a gradual loss of calcium, as well as structural changes, causing the bones to become thinner, more fragile and more likely to break. DXA is also effective in tracking the effects of treatment for osteoporosis and other conditions that cause bone loss.
- The DXA test can also assess an individual’s risk for developing fractures. The risk of fracture is affected by age, body weight, history of prior fracture, family history of osteoporotic fractures and life style issues such as cigarette smoking and excessive alcohol consumption. These factors are taken into consideration when deciding if a patient needs therapy.
How should a patient prepare for the exam?
- On the day of the exam you may eat normally. You should not take calcium supplements for at least 24 hours before your exam.
- You should wear loose, comfortable clothing, avoiding garments that have zippers, snaps or buttons made of metal. Objects such as keys or wallets that would be in the area being scanned should be removed out of your pockets.
- You may be asked to remove some or all of your clothes and to wear a gown during the exam. You may also be asked to remove jewelry, eye glasses and any metal objects or clothing that might interfere with the x-ray images.
- Inform your physician if you recently had a barium examination or have been injected with a contrast material for a computed tomography (CT) scan or radioisotope scan. You may have to wait 7 days before undergoing a DXA test.
What will I experience during and after the procedure?
- Bone density tests are a quick and painless procedure.
- Routine evaluations every two years may be needed to see a significant change in bone mineral density, decrease or increase. Few patients, such as patients on high dose steroid medication, may need a follow-up at six months. We will also mail out a recall letter every 2 years to let you know when they are due.
- Small changes may normally be observed between scans due to differences in positioning and usually are not significant.